Question

1. A car falls of a ledge and drops to the ground in 0.5 s. Let g= 10 ms-2
a. What is its speed on touching the ground?
b. What is its average speed during 0.5s?
c. How high is the ledge from the ground?

Answer 1

Answer:

Explanation:

Assuming u = 0 m/s (as no force was applied except gravity), given g = 10 m/s, t = 0.5 s

a) Using equation of downward motion,

v = u + gt

v = 0 + 10 x 0.5

v = 5 m/s

c)  Using equation of downward motion,

v² = u² + 2gh

5² = 0² +2 x 10 x h

25 = 20 x h

  h = 25 / 20 = 5 / 4 = 1.25 m

b) Average speed = Total distance / Total time

                              =  (5/4) / (0.5)

                              = 5/8 m/s = 0.625 m/s